Compactor

ABSTRACT

A self-contained engine driven vibratory plate compactor having features which lend it great maneuverability and maximal compacting capabilities under adverse conditions. It features a control system enabling an immediate and effective reversing of its direction of movement over a work surface. In preferred embodiment it includes a vibratory base plate assembly mounting a pair of transversely disposing longitudinally spaced apart exciter means to which hydraulic motors are directly connected. Rising above the plate assembly and isolated from shock resulting from its compacting movements is a superstructure which includes a prime mover, a hydraulic pump driven thereby and a selector valve immediately accessible to the operator of the compactor. A hydraulic circuit provided enables the included selector valve to function to direct fluid under pressure to one or the other of the hydraulic motors. The arrangement provides for independent rotation of the exciter means and for drive of the exciter means in opposite directions or in directions one of which is counter to the direction of drive of the other. By the means provided one can instantaneously energize an exciter means and the direction of rotation thereof will determine the direction of movement of the compactor, which will be instantaneously initiated without interference from the other.

United States Patent [191 Briggs et al.

[4 1 Aug. 12, 1975 l COMPACTOR [73] Assignee: Koehring Company, Milwaukee,

Wis.

22 Filed: Nov. 7, 1974 21 Appl. No.: 521,844

Related US. Application Data [63] Continuation of Serv No. 322,405, Jan. 10, 1973,

abandoned.

[52] US. Cl. 404/133 [51] Int. Cl. EOlC 19/34 [58] Field of Search 404/102, 113, 133, 117; 91/413; 60/488 [56] References Cited UNITED STATES PATENTS 2,044,883 6/1936 Jackson 404/102 2,347,368 4/1944 Rosen 91/413 2,655,167 10/1953 Dunkelow..... 91/413 X 2,938,438 5/1960 Hamilton 404/113 2,952,193 9/1960 Converse 404/113 3,001,458 9/1961 Croucher... 404/133 3,342,1 l8 9/1967 Beierlein 404/113 3,450,012 6/1969 Beierlein 404/133 X 3,741,669 6/1973 Harris 404/117 FOREIGN PATENTS OR APPLICATIONS 905,852 9/1962 United Kingdom 404/1 13 Primary Examiner-Nile C. Byers, Jr. Attorney, Agent, or Firm-Jerome P. Bloom [57] ABSTRACT A self-contained engine driven vibratory plate compactor having features which lend it great maneuverability and maximal compacting capabilities under adverse conditions. It features a control system enabling an immediate and effective reversing of its direction of movement over a work surface. In preferred embodiment it includes a vibratory base plate assembly mounting a pair of transversely disposing longitudinally spaced apart exciter means to which hydraulic motors are directly connected. Rising above the plate assembly and isolated from shock resulting from its compacting movements is a superstructure which includes a prime mover, a hydraulic pump driven thereby and a selector valve immediately accessible to the operator of the compactor. A hydraulic circuit provided enables the included selector valve to function to direct fluid under pressure to one or the other of the hydraulic motors. The arrangement provides for independent rotation of the exciter means and for drive of the exciter means in opposite directions or in directions one of which is counter to the direction of drive of the other. By the means provided one can instantaneously energize an exciter means and the direction of rotation thereof will determine the direction of movement of the Compactor, which will be instantaneously initiated without interference from the other.

12 Claims, 5 Drawing Figures PATENTED AUG 1 2197s SHEET SHEET FIG COMPACTOR This application is a continuation of US. application Ser. No. for US. Letters Patent 322,405, filed Jan. 10, 1973 for COMPACTOR" and now abandoned.

BACKGROUND OF THE INVENTION This invention relates to contractors equipment, and particularly to compactors guided or maneuvered across ground surface to achieve a desired density and finish to underlying compressible materials such as soil, ashalt, gravel and the like. In such devices, a work contacting plate is vibrated by exciter means and a superstructure rising above the vibratory plate includes a prime mover and connections therefrom to effect a powered operation of the exciter means.

The prior art compactor machines do have an inherent ability to travel over a work surface in response to an exerted vibratory action and this ability is used to guide or maneuver the machine over a working area. However, they have evidenced problems in their use. A particular problem has derived from the absence of an effective reversing system. This has limited their maneuverability to the extent that tamping and like operations in close quarters has proven to be extremely difficult. It is obvious, of course, that an inability to freely move a compactor in both forward and rearward senses will in any case interfere with an efficient and rapid compacting operation, particularly one that gives good results.

There have been many efforts to introduce a reversibility feature of a satisfactory nature in prior art compactors. However, the previously suggested embodiments of reversing mechanism have been less than satisfactory. Their mechanics have been such as to greatly stress the drive systems with which they have been employed and they have led to the creation of low reliability and costly compactor designs. Another disadvantage found to exist in the use of prior art compactors embodying reversing mechanisms is that the reversing action provided therein has been slow. This has resulted from the creation of systems wherein the rotating and vibrating means employed must first be brought to a full stop and then restarted in order to change direction. A consequence of the prior art practice and the necessity of causing or dealing with inertia factors between directional changes in use thereof obviously limits the skill and effectiveness with which a compactor can be used and causes increased labor costs.

Some of the prior art efforts to achieve satisfactory and effective reversibility in compactors have used hydraulic controls. However, the manner in which such controls have been applied has not led to the achievement of a smooth functioning compactor having the handling and reversing facilities such as enabled by the present invention. The prior art hydraulic control systems have not been conducive to effect control of a compactor and maximum usage of its available forces in effecting proper action thereof in tight quarters.

SUMMARY OF THE INVENTION:

A compactor according to the instant invention retains the feature of advantage which exists in prior art devices while providing an improved construction for compactors enabling a low cost unit which may be easily manipulated in both forward and reverse directions, at will, and which guarantee a high degree of effective compaction for the size and weight of the unit. The result is to facilitate optimal control of a compactors functions and an avoidance of both lost motion and erratic movement in a compacting procedure. Preferred embodiments of the invention feature a pair of inde' pendently operable exciter means which are longitudinally spaced apart and mounted in close relation to the vibratory base plate of a vibratory base assembly. Operation of either exciter means vibrates the base plate for compaction of the work. A key to their effective operation is their separate and direct drive in respectively opposite directions by hydraulic drive means, the benefits of which are enhanced by their particular positioning on the base plate. The arrangement is such to provide for immediate and interchangeable operation of a selected exciter means to the exclusion of the other whereby to provide for continuous compaction in quick movements of the compactor in the respectively" different directions which a tight working area might require.

Preferred embodiments of the invention provide compactors wherein hydraulic motors which are separately energizable in accordance with the invention are incorporated in the vibratory base assembly in a manner that they are coupled in a direct driving relation to the respective exciter means. Further, a superstructure is provided to rise above the base assembly, from which it is divorced by resilient cushioning devices and positioned thereby in elevated spaced relation to the base assembly. The superstructure mounts a prime mover and a hydraulic pump driven thereby, the output of which is commonly coupled to the respective hydraulic motors which are coupled to the respective exciter means. A simple selector valve is provided to be immediately accessible to the operator of the compactor to direct the pump output, an any one time, to a selected hydraulic motor. By such means, as will be further detailed, the motors maay be energized independently and separately of one another, thereby avoiding stress and strain on the compactor parts in the course of a reversing movement.

The system as provided by the present invention eliminates pauses as the respective motors are energized to induce a change in direction of the compactor. Further, not only is stress eliminated but inertia and other undesirable effects of a conventional reversing system is throughly minimized by the invention practice.

In the illustrative embodiment of the invention here illustrated the coupling between the hydraulic motors and the respective exciter means includes a flexible connecting device which provides for a simplified detachment and separation of parts when required yet af fords a positive drive from each motor to its related exciter means.

An unobvious result of the improvements of the present invention is that the construction provided has proven to facilitate the use of high frequency vibration in the operation of the compactor, which has enabled a reversing type unit which is light in weight and capable of achieving a level of 10,000 pounds centrifugal force. High frequency operation has, in turn, eliminated the previous tendency of a compactor machine of a reversing type to tear apart as a result of extended operation.

An object of the invention is to provide a vibratory plate compactor with instantaneous reversing capability facilitating an effective and efficient use thereof in extremely tight areas of operation.

A further object of the invention is to provide a simplified means for and method of controlling the speed and direction of movement of a compactor.

An additional object of the invention is to provide a reversing type compactor utilizing hydraulically driven exciter means which are independently and separably operable and driven in respective directions one of which is counter to the other.

An additional object of the invention is to provide a reversing type compactor wherein there are paired exciter means one of which dictates operation of the compactor in one direction and the other of which is capable of a counter movement to induce movement of the compactor in an opposite direction.

A still further object of the invention is to provide an improved compactor capable of reversible operation embodying a base plate assembly to which are connected separate and longitudinally spaced exciter means each of which is coupled directly to a hydraulic drive motor through a flexible type coupling, the drive motors being commonly powered by a hydraulic pump mounted in shock isolated spaced elevated relation to the base plate assembly.

Another object of the invention is to provide a compactor possessing the advantageous structural features, the inherent meritorious characteristics and the means and mode of use herein described.

With the above and other incidental objects in view as will more fully appear in the specification, the invention intended to be protected by Letters Patent consists of the features of construction, the parts and combinations thereof, and the mode of operation as hereinafter described or illustrated in the accompanying drawings, or their equivalents.

Referring to the accompanying drawings, wherein is shown one embodiment of the invention:

FIG. 1 is a view in perspective of a compactor in accordance with the illustrated embodiment of the invention;

FIG. 2 is a view in side elevation of the compactor of FIG. 1, partly broken away.

FIG. 3 is a top plan view of the vibrator base assembly as comprised in the compactor, the engine and related elements of the superstructure being omitted;

FIG. 4 is an exploded isometric of portions of the vibrator base assembly; and

FIG. 5 is a flow diagram of the hydraulic circuit embodied in the compactor of FIG. 1.

DESCRIPTION OF A PREFERRED EMBODIMENT:

Referring to the drawings, a compactor in accordance with the illustrated embodiment of the invention comprises a vibratory base plate formed of steel or otherwise constructed to be a heavy structured rigid member. In the case illustrated the plate 10 has a generally rectangular configuration and opposite ends bent upward in a staged manner to successively define at each end a first inclined surface portion 11 and a second more sharply inclined surface portion 12. As the under surface of the plate 10 is so formed, the leading and trailing ends of the vibratory plate are both capable of riding easily up and over any work surface to which the compactor is applied. For example, where the work surface embodies lump material, improved climbing and pre-breakup of the material can result with a simple and easy maneuvering of the compactor.

The longitudinal extent of the porton 13 of the plate 10 intermediate its turned up ends is constructed to have a flat planar configuration. As may be seen, the plate portion 13 provides the base support for the entire compactor. Note that the respective sides of the plate 10 include turned up relatively shallow lip portions 14 which define its lateral extremities. As so provided, the plate 10 has a trough-like configuration in a longitudinal sense, the sides of which trough are essentially open since the lip portions 14 extend only just above the upwardly facing floor surface of the plate.

Mounted on and extending the length of the upwardly facing floor surface of the vibratory plate 10 is a generally rectangular tube-like member 15 the ends of which respectively abut and are connected to the turned up ends 11 and 12 of the plate 10 by a welding or like process. As so connected, the member 15 becomes an integral part of the plate 10 and its ends are sealed in the joining process. The member 15 thus provides a housing immediately over the upper surface of the plate 10, which housing defines a closed exciter compartment. This compartment may be partly filled with a fluid lubricant whereby to enable a splash lubrication of embodied exciter means and bearings therefor, the details of which will be further described.

'As may be seen, the base plate assembly, including the member 15, is symmetrical to either side of a transverse center line mid way of its length. This facilitates that either end of the plate may equally serve as the leading end and with equal effectiveness.

Included in the member 15, on one side of a medial transverse plane, is a pair of aligned openings 16 which are formed in respectively opposite side walls of the member 15, which forms with the plate 10 the housing for its vibration inducing exciter means. Toward the other end of the plate 10 and to the opposite side of the described medial transverse plane, the member 15 is provided with a pair of like aligned openings 17, the

openings 17 and 16 being thus provided in a rectangular arrangement which is symmetrical to either side of said medial transverse plane. Secured, as by welding, to each of the side walls of the housing defined by the member 15, in an alternating relation to the openings 16 and 17, are three L-shaped brackets 18. The brackets 18 project outwardly of the housing wall to which they mount. The outer ends of the brackets 18 include their turned over ends in an orientation in which they have an upward angled relation to a plane parallel to the side wall of the member 15 to which they mount.

The vibratory plate 10 and the included housing defined by the member 15 form an assembly which includes within the housing a pair of longitudinally spaced apart exciter means, there being one such means at each of the mounting locations represented by the sets of openings 16 and 17. The respective exciter means are identical so that a description of one will suffice for both.

Thus, referring to the location of openings 16, a cap 19 is applied to the outer surface of one side wall of the housing defined by the member 15 to close the opening 16 therein. The cap is bolted to the abutted housing wall, with a shim 21 being provided therebetween. The cap 19 includes a reduced diameter cylindrically formed tubular portion 22 which is received in the opening 16 and accommodates, in nested relation thereto, a bearing unit 23. At the opposite side of the member the opening 16 in the side wall thereof is closed by cap member 24 including a cylindrical tubelike projected portion 25 which is accommodated within the adjacent opening 16 and nests therein a bearing means 26 similar to the bearing unit 23. The cap 24 has a central opening which is extended by the projection 25 to form a bore 27. As may be seen in the drawings, cap 24 has an external flange including bolt holes 28 through the medium of which it is bolted to the adjacent housing wall, a shim 29 being imposed therebetween. Within the compartment defined by the member 15, and extending transversely between the openings 16 in the walls thereof, is an exciter means in the form of a generally cylindrical weight 31. Extending from one end of the weight 31, in an eccentric relation to the longitudinal axis thereof, is a stub shaft 32. Extending from the opposite end of the weight, in alignment with the shaft 32, is a tubular projection 33. The latter is formed, intermediate its ends, with diametrically aligned openings 34. Shaft 32 and projection 33 align with and mount in a relatively rotatable bearing relation to the respective bearing units 23 and 26. The arrangement is one to mount the weight 31 so as to have its central longitudinal axis in an offset or misaligned relation to the openings 16 and the bearings 23 and 26. As will be obvious, on drive thereof the weight 31 will eccentrically revolve and consequently apply vibratory impulses to the base plate 10.

A hydraulic motor 35 mounts in a coupled and driving relation to the weight 31 bridging the openings 16. This motor is of a type commerically available in which hydraulic fluid supplied under pressure effects a powered rotation of its output shaft 36. In the case illustrated the motor 35 is attached directly to the end cap 24 and for this purpose has an end flange 37. Bolts inserted through the flange 37 and an interposing shim 38 are received in threaded apertures 39 in the cap 24. The mounting arrangement is such to align the output shaft 36 with the cap opening 27 whereby the projecting output shaft may extend through and beyond the cap and into a cylindrical sleeve 41 installed in the tubular projection 33 on the weight 31. The shaft 36 is provided with a splined exterior surface and the same is established in a mating engagement with the splined interior surface on the sleeve 41. The sleeve 41 is provided with diametral openings which are aligned with the openings 34 in the projection 33. A pin 42 inserted through the aligned openings 34 and 43 provides effective interconnection of the parts to insure a substantially unison rotary motion thereof. As mounted, the sleeve 41 acts as a drive coupling member and with its related parts coacts in a manner to provide therewith a substantially flexible coupling between the motor 35 and the exciter weight 31. An identical exciter means and drive mechanism is associated with the openings 17 by means and in a manner the same as those described in connection with the housing openings 16. The relative position of the parts is, however, in this case reversed. The cap 19 closing an opening 17 is on the reverse side of the housing as compared to the position of the corresponding cap 19 closing an opening 16. Similarly, the motor mounting cap 24 closing an opening 17 disposes in a sense oppositely of the cap 24 associated with an opening 16. In the case of the exciter means or weight installed between and in bridging relation to the openings 17 coupled thereto is a hydraulic motor 44. The latter while identical to motor 35 is separately identified for convenience of description. As the exciter means are mounted and the hydraulic motors connected thereto, the respective hydraulic motors 35 and 44 accordingly mount in a longitudinally spaced and laterally offset relation. As will be further understood, each motor is independently coupled in driving relation to one of the exciter means, which exciter means may be regarded as occupying forward and rearward positions in the vibrator base assembly.

While the details of the motor 35 or the motor 44 are unnecessary for an understanding of the present invention, as shown the motor 35 has a fitting 45 installed in one side to provide an inlet to the motor for directing thereto hydraulic fluid under pressure. Installed in a generally opposite side of the motor is an outlet fitting 46. Inlet and outlet fittings 47 and 48 are similarly installed in connection with the motor 44. All that need be understood for the purpose of the present disclosure is that hydraulic pressure fluid entering the motors 35 and 44 expends its energy in a rotation of. their respective output shafts and then exhausts by way of the respective outlet fittings 46 and 48. It should be understood that the hydraulic connections and the drive provided for the motors are made with a view of revolving the respective weights 31 in respectively opposite directions whereby in the one instance the weight will be driven in clockwise direction and in the other in a counterclockwise direction. In any case a single motor, when energized, is adequate to drive the coupled exciter means and effect a vibration of the plate 10. Dependent on which motor is driven and by reason of the placement and mode of operation of the related weight in the form of an exciter means the vibratory base plate assembly will receive impulses which are resolved into either a forward or reverse linear movement of the compactor unit. The direction of the movement will of course depend upon the direction of rotation of the driven weights.

Rising above the vibratory plate assembly is a superstructure embodying the power and control elements for the hydraulic motors and correspondingly of the weights 31. Only those elements directly pertaining to an understanding of the present invention will be here considered and described in detail. In general, the superstructure includes a plate 49 positioned above and in a superposing spaced relation to the vibratory base assembly. The plate 49 includes sloping wing portions 51 at its sides which extend laterally to overlap and position in a protective relation to the hydraulic motors 35 and 44 to respectively opposite sides of the housing defined by the member 15. The plate 49 and its superstructure are supported with reference to the vibratory plate assembly by means of cushioned devices 52 which are mounted between the brackets 18 and the wings 51. The cushioned devices 52 function to isolate the superstructure from the shock incident to compacting operation of the vibratory plate assembly. Further cushioning devices providing handle mounts 53 are attached to the wings 51, externally thereof. The devices 53 include means providing a place of pivotal attachment for a maneuvering handle 54 of an inverted U shape and enables the handle 54 to be swung forwardly and rearwardly of the aforementioned transverse medial plane of the vibratory plate assembly to enable appropriate guiding movement of the compactor in one direction or another.

Mounted on the top of plate 49, toward one end thereof, is a gasoline powered engine 55. The latter is of a commercial type with known structural and operating characteristics. lts operation is productive of a rotation of its output shaft 56 which projects into an engine mounted adapter housing 57. Bolted or otherwise suitably attached to the adapter housing 57 is a hydraulic pump 58. The shaft 56 is drivingly related to the pump 58 by means including a coupling sleeve and a splined shaft 61 whereby to produce an operation of the pump 58 simultaneous with an operation of the engine 55. The pump 58 is a commercially known device operative to draw fluid from a reservoir of hydraulic fluid contained in a tank 62 of angular shape mounted on the plate 49 to one end of engine 55. The pump 58 is connected to the tank 62 by way of a tank outlet fitting 63 and a flexible connecting line 64. As here provided, operation of the pump 58 draws fluid from the tank 62 and directs it, under pressure, through a line 65 to a valve 66 located in an overhead relation to the engine and hydraulic tank components. A fitting 67 connects the line 65 to valve 66 and constitutes a valve inlet. As shown valve 66 is suspended from a plate 68 mounted between elements of a roll bar assembly 69 which rises from the plate 49 to assume a protective relation to the engine, pump and other elements of the superstructure. A vertically extending plate portion 71 is welded across the roll bar assembly and has an opening 72 through which a crane or the like may be used to lift the compactor. Another portion of plate 68 provides a mounting for the engine air cleaner 73, locating the cleaner well above the engine to insure that it receives relatively clean air. Also mounted to a portion of the plate 68, along side the air cleaner 73, is a throttle control 74 effective in a manner which it is unnecessary here to consider to vary the speed of operation of the engine 55. The air cleaner 73 and throttle control 74 are located on one side of the vertical plate portion 71, and the valve 66 is located on the opposite side and in an underslung relation to the plate 68.

The valve is a slide or spool type valve of known character which provides that hydraulic fluid admitted by way of the fitting 67 may be directed selectively to valve outlet bosses 75 or 76 or to a recirculating boss outlet 77. The valve conventionally embodies a spool element (not shown) which terminates in a rod 78 projecting from one end of its housing to have a handle 79 connected thereto. At its lower end the handle 79 pivotally mounts to a valve mounted bracket 81 and projects through an opening 82 in the plate 68 to terminate in a manually operable and accessible knob portion 83 projecting uppermost of the compactor. As will be understood, a manipulation of the handle 79 may be effected to provide for an axial positioning and repositioning of the valve spool element through the medium of the rod 78, thereby to locate the spool for selective control of the direction of flow of the hydraulic fluid which is delivered to the valve under pressure. As is evident, upwardly projecting handle 79 and the throttle element 74 constitute principal controls of the compactor which are conveniently accessible to the hand of the operator.

A flexible fluid conducting line 84 connects the valve outlet boss 75 to the inlet fitting 45 of the hydraulic motor 35. The outlet boss 76 is similarly directly connected with the inlet fitting 47 of the motor 44 by way of a flexible fluid conducting line 85. A line 86 provides a connection between theoutlet 77 and the fluid storage tank 62.

Accordingly, under the control of the handle 79, the spool element in valve 66 has several control positions. In the first or neutral position, hydraulic fluid supplied by the pump 58 is by-passed to the storage tank 62. In a second position of the spool, hydraulic fluid directed to the valve 66 under pressure is routed by way of the boss and line 84 to the hydraulic motor 35, the result of which is to power the connected eccentric weight constituting one of the exciter means in connection with the vibratory plate assembly. in a third control position the hydraulic fluid under pressure reaching the valve 66 is caused to be directed to the valve outlet 76 and conducted to the hydraulic motor 44 by way of the line 85. It may be seen, therefore, that motors 35 and 44 are independently and separately operable, with their operation being exclusive of one another. By the arrangement provided it is clear that when fluid is directed to one of the motors 35 or 44, the motor to which the fluid under pressure is directed will be instantaneously energized and the motor from which the fluid is instantaneously cut off will be immediately deenergized. Thus each motor not only operates independently of the other and drives its related weight in a direction counter to the direction of the other but it is also capable of having the effect thereof immediately nullified by an appropriate split second adjustment of the selector valves.

Of course, with the valve 66 in a neutral position, neither hydraulic motor will be energized.

The hydraulic motor outlet fittings 46 and 48 are suitably connected for return flow of the fluid in the hydraulic system to the tank 62. More specifically, the outlet fitting 46 is connected to the tank 62 by way of a line 87 leading through the plate 49 to the underside of the tank. A corresponding or similar connection (not here shown) is provided from the fitting 48 to the storage tank. In this connection it will be understood that the hydraulic circuit as here provided defines a substantially closed system in which fluid drawn from the reservoir in tank 62 is returned to the tank for reuse, the direction of flow being determined by the position of the selector valve 66 andd occurring by way of either the motor 35, the motor 44 or by a by-passing of both motors. The diagram of FIG. 5 schematically illustrates the relation of the elements in the simple hydraulic control system of the present invention. As shown, the pump 58 is operative to draw fluid from the tank 62 and force it under pressure through line 65 to the valve 66. The position of the valve, as determined by the setting of the control handle 79, will direct the fluid under pressure to one of the lines 84, 85 or 86 which lead respectively to hydraulic motor 35, hydraulic motor 44 and tank 62. As described, when it is desired that the compactor be in an idling condition, the fluid is bypassed back to the tank 62 by the setting of the valve 66. With the valve 66 having its spool member positioned to direct flow to either of the motors 35 or 44, compaction will take place and simultaneously therewith there will occur a linear motion of the compactor in either a forward or rearward direction, depending upon which hydraulic motor has been energized.

To summarize the apparatus above described, a compactor in accordance with the invention provides a vibratory base assembly embodying in immediate adjacent relation to and spaced longitudinally'of its upper surface a pair of exciter means defined by the weights 31. The exciter means are spaced apart, the one to pre scribe a forward movement on operation thereof and the other to prescribe an opposite or rearward movement on operation thereof. A separate fluid motor is directly coupled to the eccentric weight defining each exciter means through a flexible type splined drive coupling. A directional control valve governs flow of fluid under pressure to either the forward or the rearward disposing motor, depending on the position of the valve control handle. Dependent on the motor energized, the associated eccentric weight will be revolved. As the weight revolves it transmits a high speed vibratory motion to the base plate 10 which in turn functions to compact the work surface thereunder. As the work surface becomes more firm in the compacting operation, the direction of rotation of the particular exciting means in the form of the eccentric weight 31 then energized will cause the entire compactor to move in the direction which the rotation prescribes. Should it be desired to reverse the direction of movement of the compactor, the valve 66 may have its control spool shifted to a position to direct fluid under pressure to the other motor which to this point has been deenergized. As the control valve is shifted, the motor which has been previously energized is substantially instantaneously deenergized while the motor which was originally deenergized is substantially instantaneously energized. The net effect is that there is no pause or necessity for pause in order that the previously energized motor and associated exciter means be stabilized and caused to assume a stationary condition before the newly energized motor commences to function. This is due to the fact that not only is there an instantaneous switching of motor power but each motor has its own direct drive coupling it to the associated eccentric weight and it is thereby enabled to begin its operation from a fully stopped position. The construction and arrangement of parts here provided avoids the necessity for and the problems inherent in the use of prior art reversing mechanisms, whether mechanical or hydraulic. The reversing procedure is such as to greatly facilitate the use of the compactor in close quarters or tight areas where frequent changes of direction may be desirable to minimize the time necessary for achieving a desired end result.

As the superstructure of the compactor is here provided, the same is substantially isolated from the action of the vibratory base assembly and there is a minimal transmission of the vibratory impulses thereto. The use of flexible couplings between the hydraulic components insures that the transmission of vibratory impulses back to the superstructure components will be of a minimal nature and have no particular deleterious effect.

Particular attention is directed to the fact that the position of the exciter means in reference to the base plate and as housed on the base plate provides a device of sturdy construction and the low center of gravity provided helps make the reversing control capabilities of the compactor most effective and the compactor most easily maneuverable. That the hydraulic motors are integrated into the vibratory base assembly and mount in a directly coupled relation to the exciter means therein insures their most effective and immediate operation as and when required.

Dual controls in the upper superstructure place a] operations under convenient control of an operator Throttle 74 adjusts engine speed and hence regulate the rate of compaction of a work surface and the speer of travel of the compactor over the work surface. Tht valve controls, moreover, facilitate an instantaneou: location of the compacting force of the unit as hert provided.

It must be emphasized that the hydraulic motors em ployed do not reverse direction and that when they are energized they are starting from a dead stop. There i: no shifting from a rotation of the eccentric weight ir one direction to an opposite direction. Therefore there is basically no pause required for direction change When direction must be changed, the motor to the opposite end of the vibratory plate assembly is caused tc be energized from a dead stop. Thus only one motor is in any instance effectively operating and the directior of its rotation will determine the direction of movement of the compactor. The compactor is significantly different and better than a compactor which may use two vibrators which run in the same direction. By the invention maximum centrifugal force action is enabled in use of opposite rotation for each of the respective weight: 31.

As mentioned previously, the system and construction here provided has enabled that a relatively light compactor machine weight can be used to achieve a substantial compacting force. For example, the invention contemplates the achievement of as much as 5 ,000 vibrations per minute with an increase of the resultant force to 10,000 pounds centrifugal force. The net result has been a high frequency machine which can be operated in relatively opposite directions which are substantially instantaneously changed in a manner and under conditions as to avoid tearing the machine apart or damage to components thereof.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

l. A vibratory plate compactor including a work engaging vibratory base plate, a pair of exciter means, means mounting said exciter means in a closely adjacent connected relation to and for rotation on said base plate, said exciter means being positioned in a longitudinally spaced relation and having their axes of rotation extended in a sense transversely of said base plate, a separate motor connected with each exciter means having in connection therewith means for a separate and independent drive thereof, said motors being operable independently of one another and connected to drive the associated exciter means in respectively opposite directions, and control means associated with said motor drive means providing that one motor which is operating may be deenergized and the other motor energized substantially simultaneously.

2. A vibratory plate compactor according to claim 1 characterized by the respective exciter means being respectively disposed adjacent an opposite end of said base plate and one said exciter means being arranged to rotate in a direction counterclockwise to the direction of rotation of the other and the drive of either of said exciter means by its related motor being effective to move the compactor in the direction determined by the direction of the most adjacent end of said base plate.

3. Apparatus as in claim 2 characterized by said exciter means including a coupling portion eccentric to one end thereof and means providing a direct axial connection between said coupling portion and the drive shaft of its related motor.

4. A vibratory plate compactor as in claim 1 characterized by said motors being hydraulic motors and said drive means for said motors including means mounted in a spaced elevated relation to said base plate and in spaced relation to said motors by resilient shock absorbing supports and arranged to commonly furnish motive power to drive said motors and said control means being incorporated in said drive means to provide for a substantially instantaneous switch of the motive power from one to the other of said motors, as needs require.

5. Apparatus as in claim 4 characterized by said drive means including a hydraulic pump connected to deliver fluid under pressure to drive said motors and said control means comprising a selector valve interposed between said pump and said motors and operable to simultaneously switch the direction of flow of fluid under pressure from one to the other of said motors.

6. Apparatus as in claim 5 characterized by means in connection with said base plate providing a substantially sealed compartment for said exciter means and mounting said motors in an adjacent end spaced relation to the related exciter means, there being means providing an eccentric driving connection between said motors and the respectively related exciter means interiorly of said compartment.

7. Apparatus as in claim 6 characterized by said vibratory base plate being provided with a substantially flat planar portion intermediate its ends serving as a base for the compactor and the opposite ends of said base plate being bent upward in a configuration that either end may act as the leading end of the compactor in respect to its continuing operation in forward and reverse sense.

8. Apparatus as in claim 6 characterized by said drive means interconnecting a drive motor with its associated exciter means including coaxial telescoping parts having an interconnection through the medium of a transversely inserted coupling pin.

9. Apparatus as in claim 1 wherein said motors are hydraulic motors and said compactor is characterized by a superstructure rising above said exciter means and said motors in a superposed spaced relation thereto, resilient supports mounting said superstructure in connection with said base plate and said superstructure mounting a prime mover, a hydraulic pump operated thereby, and a selector valve receiving fluid under pressure from said pump and operable to provide said control means, and flexible lines for conducting fluid under pressure leading from said valve to the respective motors, said valve being operable to substantially instantaneously change the direction of flow of said fluid under pressure from one line to another.

10. A vibratory plate compactor according to claim 1 characterized by each said motor being a hydraulic motor coupled directly to and in line with means eccentrically positioned in connection with one end of a weight constituting the associated exciter means, said drive means for said motors being provided by an engine driven hydraulic pump, a base mounting said pump having a platelike form and being mounted in turn in an interconnected spaced elevated relation to said base plate, said exciter means and said motors by resilient supporting elements, said base mounting said pump mounting thereon a reservoir of hydraulic fluid connected in a hydraulic circuit for supplying fluid to said pump for delivery thereby under pressure to said motors, and said control means including a selector valve interposed between said pump and said motors and said reservoir and providing a single device through the medium of which fluid under pressure may be selectively directed to determine the operating condition and the direction of or lack of direction of movement of said compactor.

11. Apparatus as in claim 1 characterized by means in connection with and extending longitudinally of the uppermost surface of said vibratory base plate, in intersecting relation to a transverse mid portion thereof, defining a housing for said exciter means, said exciter means being in the form of eccentrically mounted weights including to one end thereof, in eccentric position to its longitudinal axis, a coupling portion, said motors being hydraulic motors respectively positioned on reverse sides of said housing and in line with the eccentrically positioned coupling portion of its associated exciter means, each said motor having a drive shaft extending therefrom to project inwardly of said housing and being coupled within said housing by telescopically related means in association with the adjacent coupling portion of the eccentric weight in line therewith.

12. A vibratory plate compactor as in claim 11 characterized by said drive means including means for delivering fluid under pressure to the respective motors supported on a plate mounted in spaced elevated relation to said vibratory base plate by resilient supports, said control means comprising a selector valve for directing fluid under pressure to one of said motors while preventing the flow of fluid under pressure to the other said motors and said elevated plate including wing-like portions extending in an overlapping protective relation to said motors.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 899 26 3 Dated PaLlCIUSt l2 19 75 Inventor(s) Euqene C. Briqqs; Lee Reichel It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Col. 1., line 3, "Sc-ammo. is deleted in the first instance and inserted in the same line after Patent Col. 1, line 12 ashalt is corrected to read asphalt Col. 2, line 36, "an is corrected to read at Col. 2 line 38, maay" is corrected to read may Col. 2 line 47, throughly is corrected to read thoroughly Col. 5, line 49, an is inserted. following "provides".

Col. 8, line 44, "andd" is corrected to read and Col. 10, line 1, al is corrected to read all Col. 10, line 2, a period is inserted following "operator".

Col. 10, line 3, "regulate" is corrected to read regulates Col. 10, line 4, spee" is corrected to read speed Col. 10, line 5, "th" is corrected to read The Col. 10 line 6, instantaneou" is corrected to read instantaneous Q Col. 10 line 7 "her" is corrected to read here Col. 10 line 9 a hyphen is inserted following em (Continued on Page 2) UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent rsqqym Dated August 12, 1975 t (s) Euqene c. Briqds; Lee Reichel It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

. Col. 10 line 10 "ar" is corrected to read are.

Col. 10, line 11, "i is corrected to read is Col. 10, line 12, i" is corrected to read in Col. 10 line 13, ther" is corrected to read there Col. 10, line 14, a period is inserted following "change".

Col. 10 line 15 a hyphen is inserted following 013". Col. 10 line 16 "t is corrected. to read to Col.. 10 line 17, "i" is corrected to read is Col. 10, line 18, "directio" is corrected to read direction Col. 10 line 19 movemen is corrected to read movement Col. 10 line 27, "ligh" is corrected to read light Col. 12, line 12, "platelike" is corrected to read C plate-like fiigncd and Scaled this sixth D y of Jafiuary1976 [SEAL] Attest:

RUTH c. MASON C. MARSHALL DANN Arresting Officer (mnmissiuner of Parents and Trademarks 

1. A vibratory plate compactor including a work engaging vibratory base plate, a pair of exciter means, means mounting said exciter means in a closely adjacent connected relation to and for rotation on said base plate, said exciter means being positioned in a longitudinally spaced relation and having their axes of rotation extended in a sense transversely of said base plate, a separate motor connected with each exciter means having in connection therewith means for a separate and independent drive thereof, said motors being operable independently of one another and connected to drive the associated exciter means in respectively opposite directions, and Control means associated with said motor drive means providing that one motor which is operating may be deenergized and the other motor energized substantially simultaneously.
 2. A vibratory plate compactor according to claim 1 characterized by the respective exciter means being respectively disposed adjacent an opposite end of said base plate and one said exciter means being arranged to rotate in a direction counterclockwise to the direction of rotation of the other and the drive of either of said exciter means by its related motor being effective to move the compactor in the direction determined by the direction of the most adjacent end of said base plate.
 3. Apparatus as in claim 2 characterized by said exciter means including a coupling portion eccentric to one end thereof and means providing a direct axial connection between said coupling portion and the drive shaft of its related motor.
 4. A vibratory plate compactor as in claim 1 characterized by said motors being hydraulic motors and said drive means for said motors including means mounted in a spaced elevated relation to said base plate and in spaced relation to said motors by resilient shock absorbing supports and arranged to commonly furnish motive power to drive said motors and said control means being incorporated in said drive means to provide for a substantially instantaneous switch of the motive power from one to the other of said motors, as needs require.
 5. Apparatus as in claim 4 characterized by said drive means including a hydraulic pump connected to deliver fluid under pressure to drive said motors and said control means comprising a selector valve interposed between said pump and said motors and operable to simultaneously switch the direction of flow of fluid under pressure from one to the other of said motors.
 6. Apparatus as in claim 5 characterized by means in connection with said base plate providing a substantially sealed compartment for said exciter means and mounting said motors in an adjacent end spaced relation to the related exciter means, there being means providing an eccentric driving connection between said motors and the respectively related exciter means interiorly of said compartment.
 7. Apparatus as in claim 6 characterized by said vibratory base plate being provided with a substantially flat planar portion intermediate its ends serving as a base for the compactor and the opposite ends of said base plate being bent upward in a configuration that either end may act as the leading end of the compactor in respect to its continuing operation in forward and reverse sense.
 8. Apparatus as in claim 6 characterized by said drive means interconnecting a drive motor with its associated exciter means including coaxial telescoping parts having an interconnection through the medium of a transversely inserted coupling pin.
 9. Apparatus as in claim 1 wherein said motors are hydraulic motors and said compactor is characterized by a superstructure rising above said exciter means and said motors in a superposed spaced relation thereto, resilient supports mounting said superstructure in connection with said base plate and said superstructure mounting a prime mover, a hydraulic pump operated thereby, and a selector valve receiving fluid under pressure from said pump and operable to provide said control means, and flexible lines for conducting fluid under pressure leading from said valve to the respective motors, said valve being operable to substantially instantaneously change the direction of flow of said fluid under pressure from one line to another.
 10. A vibratory plate compactor according to claim 1 characterized by each said motor being a hydraulic motor coupled directly to and in line with means eccentrically positioned in connection with one end of a weight constituting the associated exciter means, said drive means for said motors being provided by an engine driven hydraulic pump, a base mounting said pump having a platelike form and being mounted in turn in an intercoNnected spaced elevated relation to said base plate, said exciter means and said motors by resilient supporting elements, said base mounting said pump mounting thereon a reservoir of hydraulic fluid connected in a hydraulic circuit for supplying fluid to said pump for delivery thereby under pressure to said motors, and said control means including a selector valve interposed between said pump and said motors and said reservoir and providing a single device through the medium of which fluid under pressure may be selectively directed to determine the operating condition and the direction of or lack of direction of movement of said compactor.
 11. Apparatus as in claim 1 characterized by means in connection with and extending longitudinally of the uppermost surface of said vibratory base plate, in intersecting relation to a transverse mid portion thereof, defining a housing for said exciter means, said exciter means being in the form of eccentrically mounted weights including to one end thereof, in eccentric position to its longitudinal axis, a coupling portion, said motors being hydraulic motors respectively positioned on reverse sides of said housing and in line with the eccentrically positioned coupling portion of its associated exciter means, each said motor having a drive shaft extending therefrom to project inwardly of said housing and being coupled within said housing by telescopically related means in association with the adjacent coupling portion of the eccentric weight in line therewith.
 12. A vibratory plate compactor as in claim 11 characterized by said drive means including means for delivering fluid under pressure to the respective motors supported on a plate mounted in spaced elevated relation to said vibratory base plate by resilient supports, said control means comprising a selector valve for directing fluid under pressure to one of said motors while preventing the flow of fluid under pressure to the other said motors and said elevated plate including wing-like portions extending in an overlapping protective relation to said motors. 